MissionTwenty-five
years ago, scientists made a stunning discovery on the bottom of
the Pacific Ocean that forever changed our understanding of our
planet, and life on it. They discovered the first deep-sea hydrothermal vents,
andto their complete surprisea lush community of exotic
life thriving around them.

Dive and Discovers Expedition 6 returns to the Galápagos
Rift, where seafloor hydrothermal vents were first found in 1977.
The discovery of vents spewing warm, mineral-rich fluids into the
ocean helped explain why the ocean is salty and how our planet
ventilates its great internal heat. The astonishing ecosystems nourished
by the vents revolutionized scientific thinking about where and how life could
exist.

As part of the National Oceanic and Atmospheric Administration (NOAA) Ocean Exploration Program, scientists on Expedition 6 will return to see how the Galápagos Rift hydrothermal vent communities have changed. They will carry out detailed mapping and sampling, and search for new animal communities and black-smoker vents along still-unexplored areas of the Galápagos Rift.

Join scientists, students, engineers and
the ship’s crew
on board Woods Hole Oceanographic Institution’s RV Atlantis as
they use the submersible Alvin, an autonomous underwater
vehicle named ABE, and the latest in high-tech oceanographic
instruments. They will explore the site that made history 25
years ago and search for other sites of hydrothermal activity
and animal communities.

Objectives
Expedition 6 returns to the Galápagos
Rift at 86°W, where oceanographers in 1977 made one of the
most revolutionary discoveries about our planet -- deep-sea
hydrothermal vents. A main objective of this cruise is to investigate
how the vents and their animal and microbial communities have
changed over the past 25 years.

Hydrothermal vent areas are among the most
dynamic, constantly changing places on Earth. They are fueled
by the heat of magma welling up from Earth’s mantle and
erupting on the seafloor. As the heat varies, different chemical
reactions take place between seawater and hot rocks in the
ocean crust. As the heat and available chemicals change, so
do the types and amounts of microbes that feed on the chemicals.
And that affects populations of higher animals that either
feed on the microbes or symbiotically maintain them inside
their bodies.

The changes at hydrothermal vents involve many different, interrelated
organisms and processes. So Expedition 6 will have many different
types of scientists, working together, to figure out how vents
and vent life interact and operate.

Several types of biologists will be aboard.
Ecologists will study changes in Galápagos Rift vent communities that
have occurred over the past 25 years, and how animals interact
with each other. Microbiologists will study microbes, which use
harsh chemicals in vent fluids as sources of energy. Geneticists
will sample animal tissue to analyze their DNA and RNA and compare
how Galápagos vent animals are related to animals elsewhere
on mid-ocean ridges in the Pacific, Atlantic, and Indian Oceans.
Chemists will study changes in the chemical composition of the
Galápagos Rift hydrothermal fluids over the last 25 years.
Geologists will analyze data on board to map the vent sites and
see how they compare to other vent areas around the world.

Expedition 6 scientists will primarily use the deep-diving submersible
Alvin to study the vents and sample vent animals and fluids.
They will also use ABE, the Autonomous Benthic Explorer, to produce
highly detailed maps of seafloor and to search for new vents.

The first black-smoker chimney ever seen by humans photographed
at 21°N in 1979. (Photo by Dudley Foster, WHOI)

An important objective of Expedition
6 is to explore other regions of the Galápagos Rift, 200 nautical miles west of the
original vent sites, where volcanic eruptions may have occurred
recently. Scientists will search for black smoker chimneys, whose
fluids are hundreds of degrees Celsius hotter than those emanating
from the vents at 86°W. Black smokers have been found at
deep-sea vent sites elsewhere on Earth, but not on the Galápagos
Rift.

To search for new vents, scientists will
use sensitive instruments called CTDs (stands for Conductivity,
Temperature, Depth) and MAPRs (Miniature Autonomous Plume Recorders)
to look for the plumes of slightly warm and particle-rich water
that rise from hydrothermal vents -- just like columns of vapor
rising from smokestacks. In the dark depths of the oceans,
these instruments can “see” cloudy
water and can detect small telltale differences in the temperature
and other physical properties of the water. They will also use
a new, digital deep-sea camera system to search for new vents
and to scout out new areas for Alvin and ABE to investigate.

Each day will bring new samples, new discoveries,
and new ideas about how hydrothermal vents at the Galápagos
Rift have changed since they were first discovered, and new
insights into how life evolves in these extreme environments
on the deep-sea floor.